Domain and Range Real Life

A student worked out at a gym continuously for 50 minutes. The graph shows the remaining percentage of the workout as a linear function of x, the time in minutes. Which answer choice best describes the domain and range of the function for this situation?

• Domain: all real numbers greater than or equal to 0 and less than or equal to 100.

  Range: all real numbers greater than or equal to 0 and less than or equal to 50.

• Domain: {-2}

  Range: {100}

• Domain: all real numbers greater than or equal to 0 and less than or equal to 50.

  Range: all real numbers greater than or equal to 0 and less than or equal to 100.

• Domain: {100}

  Range: {-2}

The daily cost of hiring a plumber, y, to work x hours on a repair project can be modeled using a linear function. The plumber charges a fixed cost of $80 plus an additional cost of $45 per hour. The plumber works a maximum of 8 hours per day. For one day of work, what is the range of the function for this situation?

A set of weights includes a 45 lb barbell and 6 pairs of weight plate. Each pair of plates weighs 20 lb. If x pairs of plate are added to the barbell, the total weight of the barbell and plates in pounds can be represented by f(x)=20x+45. What is the range of the function in this situation?

• {0, 1, 2, 3, 4, 5, 6,}

• {45, 65, 85, 105, 125, 145, 165}

• {0, 2, 4, 6}

• {45, 55, 65, 75,85,95}

Select TWO correct answers.

Domain

​ (a)  

Range

​ (b)  

• The domain of the function is {0,1,2,3,4,5}

• The range of the function {0,96,192,288,384,480}

• The domain of the function is all real numbers

• The domain of the function {0,96,192,288,384,480}

• The range of the function {0,1,2,3,4,5}

• The range of the function is all real numbers.

A student borrowed $480 from a friend. He agreed to make monthly payments of $96 with no interest until the loan balance was paid off. The function shown models this situation, where f(x) represents the remaining loan balance in dollars after the student has made x monthly payments. Which statements are true about the domain and range of the function for this situation? Select the correct answers.

• D: {0, 1, 2, 3, 4, 5}

• R: {0, 96, 192, 288, 384, 480}

• D: all real numbers

• R: {0, 1, 2, 3, 4, 5}

• {0, 96, 192, 288, 384, 480}

• D: {0, 96, 192, 288, 384, 480}

• R: all real numbers

Answer explanation

Domain - x values

Range - y values

Real-world examples = apply common sense and judgements

Speedy Boat Rental charges a $15 deposit fee plus $2 for each hour of use to rent a paddle boat. The equation: C=2h+15. If Frank has $33 to spend, what is the domain of the situation?

• 0 < x < 9

• 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

• 15, 17, 19, 21, 23, 25, 27, 29, 31, 33

• 0 < y < 33

If I join the gym for a start up fee of $40 and monthly fee of $10, what is the range? Equation: f(x) = 40+10x

• -4, -3, -2, -1, 0.....

• $10, $20, $30, $40......

• 0, 1, 2, 3.....

• $40, $50, $60.....

Mario has and iTunes gift card worth $20.00. He uses the formula    y=0.99x to determine y, the total cost for x number of songs. What is the domain for the situation?

• All integers between 0 and 20

• All real numbers between 0 and 19.80

• All integers greater than 0

• All integers between 0 and 250

• Function
• Not a Function